`6.02xx10^(20)` molecules of urea are present in `100 mL` solution. The concentration of urea solution is:

Options

A. `0.001M`
B. `0.01M`
C. `0.02M`
D. `0.1M`.

Explanation

To find the concentration of the urea solution, we need to follow these steps:

1. **Convert the volume of the solution from milliliters to liters.**
2. **Calculate the number of moles of urea using Avogadro's number.**
3. **Determine the molar concentration using the formula for molarity.**

Let's go through each step in detail:

### Step 1: Convert the volume of the solution from milliliters to liters
The given volume of the solution is 100 mL. We need to convert this to liters.

\[ 100 \, \text{mL} = 100 \times 10^{-3} \, \text{L} = 0.1 \, \text{L} \]

### Step 2: Calculate the number of moles of urea
We are given the number of molecules of urea as \( 6.02 \times 10^{20} \).

To find the number of moles, we use Avogadro's number, which is \( 6.022 \times 10^{23} \) molecules per mole.

\[ \text{Number of moles} = \frac{\text{Number of molecules}}{\text{Avogadro's number}} \]

\[ \text{Number of moles} = \frac{6.02 \times 10^{20}}{6.022 \times 10^{23}} \]

\[ \text{Number of moles} = \frac{6.02}{6.022} \times 10^{20 - 23} \]

\[ \text{Number of moles} \approx 1 \times 10^{-3} \]

### Step 3: Determine the molar concentration
Molar concentration (M) is given by the formula:

\[ \text{Molarity} = \frac{\text{Number of moles of solute}}{\text{Volume of solution in liters}} \]

From Step 1, the volume of the solution is \( 0.1 \, \text{L} \).

From Step 2, the number of moles of urea is \( 1 \times 10^{-3} \).

\[ \text{Molarity} = \frac{1 \times 10^{-3}}{0.1} \]

\[ \text{Molarity} = 1 \times 10^{-2} \]

\[ \text{Molarity} = 0.01 \, \text{M} \]

Therefore, the concentration of the urea solution is \( 0.01 \, \text{M} \).